Boils.—Boils are very common in the tropics and occur especially in people who have been run down. They are most frequent during or after the rains and especially in the course of hot, damp summers. In Egypt the so-called Nile boil is quite a feature of the country. In the tropics boils are often multiple and a very favourite site is the buttocks. Any part, however, which is apt to be bathed in sweat is liable to infection. A boil on the face may apparently result from the bite of a mosquito or other blood-sucking insect.
Prophylaxis.—Protect from insect bites and treat even the most trivial of skin lesions with tincture of iodine. Keep the skin clean and change the underclothing frequently. If a boil occurs cover it with a small dressing so that other parts of the skin may not be affected. A change of climate is often the only thing that will do good in the case of a person afflicted with crops of boils.
Treatment.—It is sometimes possible to abort a boil by dipping a sharpened wooden match or a toothpick into pure carbolic acid and thrusting it repeatedly into the heart of the swelling. If the boil has somewhat developed hot fomentations and moist dressings should be applied and iodine should be painted on the skin round the boil. As a rule it is wiser not to open a boil, even when it has suppurated. It is best to let it burst and then to dress it carefully with a boric poultice, which should be frequently changed. Treatment with vaccines has come into vogue and is sometimes very helpful. Sulphide of calcium pills, one grain in each, three times a day, are often given and are said to have a prophylactic effect, but a preparation known as stannoxyl and used in the form of tablets is to be preferred. The usual dose is four tablets the first day, six the second, and eight on subsequent days. The drug is somewhat constipating. A remedy more easily obtained and which is said to be distinctly beneficial is dilute sulphuric acid. It should be taken in doses of twenty to thirty drops, well diluted, every four hours. The general health requires attention and lemon juice, plenty of green vegetables and tonics should be taken.
Carbuncles.—A carbuncle is of the same nature as a boil, but is a more serious complaint, and it is distinguished from a boil by the fact that it opens by several mouths.
To promote ripening of the carbuncle and the separation of the core or dead piece of tissue, poultices and hot fomentations should be freely applied, and if the core can be seen it should be removed, if possible, by a pair of forceps.
To facilitate removal of the core it is sometimes advisable to cut through the skin separating the openings; there may be some slight bleeding, but it will cease after a short time.
Opium may be given to relieve acute suffering. The bowels should be kept well open. A generous diet must be given; tonics of iron, quinine and arsenic are needed, and alcohol may prove necessary.
Carbuncles rarely appear except in people much broken down in health, and their presence is an indication that the sufferer should return to his own country and seek skilled advice.
Chigger.—The chigger is not itself a disease but is a sand-flea producing a condition known by the long name of dermatophiliasis. It is a veritable pest in parts of South America and all over tropical Africa. The insect is like the common flea but smaller, lives in dry sandy soil and sucks the blood of mammals, especially pigs. After impregnation the female burrows into the skin of a mammal or bird, and, nourished by blood, proceeds to ovulation. Her abdomen becomes filled with ripe eggs and enormously distended till it looks like a small pea. Eventually the eggs escape through the opening of the skin and hatch into larvæ which in due time become adult fleas.
Symptoms.—In man the feet are the part most frequently affected, the chiggers being found between the toes and under the toe nails. When people sleep on the ground other parts of the body may become affected and large numbers of chiggers may be present at one time. There is itching and irritation at the place of invasion, and when the latter is examined a little dark dot will be seen. This is the posterior end of the female flea, which is lying head downwards in her burrow. If not removed suppuration occurs round her distended abdomen and the skin gets much inflamed and swollen. When the eggs have been discharged ulceration takes place and the flea is expelled. A small sore, however, is left which is very liable to get contaminated, and, if neglected, may lead to very severe complications.